class_docstr: A subgraph of a TensorFlow computational graph.
  
  TensorFlow graphs are often too low-level to represent our conceptual
  understanding of a model
  
  OverlayGraph can be used to represent a simplified version of a TensorFlow
  graph. Each node corresponds to a node in the original TensorFlow graph, and
  edges correspond to paths through the original graph.
code: def collapse_structures(self, structure_map):
      keep_nodes = [
          node.name
          for node in self.nodes
          if not any(
              node in structure.children
              for structure in structure_map.values()
          )
          or node in structure_map
      ]
  
      new_overlay = self.filter(keep_nodes)
  
      for node in structure_map:
          new_overlay[node].sub_structure = structure_map[node]
  
      return new_overlay
  
imports: from collections import defaultdict
  import numpy
  import tensorflow
label_desc: Use image node_id 11 for calling the OverlayGraph obj's underlying member method code with example usage: obj.collapse_structures(structure_map) and returns: new_overlay